If `vecA= hati+2hatj+3hatk, vecB=-hati+hatj + 4hatk and vecC= 3hati-3hatj-12hatk`, then find the angle between the vector `(vecA+vecB+vecC) and (vecAxx vecB)` in degrees.

Explanation

Let `vecP = vecA + vecB+vecC= 3hati-5hatk and vecQ= vecAxx vecB= |{:(hati,,hatj,,hatk),(1,,2,,3),(-1,,1,,4):}|= 5hati-7hatj+3hatk`
Angle between `vecP & vecQ` is given by `cos theta = (vecP*vecQ)/(PQ) = (15-15)/(PQ) = 0 rArr theta = 90^(@)`